ST. PETERSBURG, Oct. 30 (Xinhua) -- The floating dock PD-50 in the Murmansk region of Russia went under water on Tuesday. During the incident, a crane fell on the deck of the Russian aircraft carrier "Admiral Kuznetsov," which was under repair in the dock, and left a five-meter hole.

Four people were injured during the incident with the sunken dock, one person is missing. The ship was safely evacuated, along with 71 people.

RIA Novosti reports that the crane that damaged the deck did not destroy any important ship structures, thus scheduled repair will be completed in 2021 as planned.

The sunken dock was the largest in the region, it had a lifting capacity of 80,000 tons. Its size is similar to the size of the Red Square in Moscow. The cause of the flooding was a power outage.

"Admiral Kuznetsov" is currently the only aircraft carrier in the Russian Navy. It has been in service in the Northern Fleet since 1991. The ship's total displacement is 59,100 tons, length-306 m, width-72 m, speed-up to 29 knots, crew-1,980 people.